In the manufacture of nonwoven fabrics, fibrous webs comprising loose arrays of fibers are subjected to various procedures for bonding, rearranging, and/or interlocking of the fibers. The quality of the nonwoven fabric product is heavily dependent upon the quality of the fibrous web feed. Thus, weight, orientation of fibers, and uniformity of the product are functions of the corresponding properties of the feed web. Further, the speed at which the feed web can be produced has a significant influence on the economics of the process for producing the nonwoven fabric. Other things being equal, processing cost per unit is inversly proportional to throughput rate. For this reason, there is considerable economic incentive for developing high speed web-forming capabilities.
The present invention provides a process and apparatus that can produce fibrous webs, including very light weight webs, of excellent uniformity at extremely high rates of speed, thereby providing the means for simultaneous unit cost reduction and quality improvement in nonwoven processes which utilize the invention.
The invention comprises a combination of elements, each of which can be optimized to perform its assigned task(s) effectively and efficiently so that the invention can be employed to produce fibrous webs of at least as high quality as any fibrous webs that could be produced by the known prior art, and at the same time, such high quality webs can be produced at throughput rates unattainable by the prior art.